Re: getting ready to shed...
If she's already refused one meal (apparently due to impending shed) then I would probably choose to skip the next until she's finished. Some snakes don't care and will eat anytime...others are picky and won't eat until they're "normal" again. You just gotta know your snake.
You didn't mention what the humidity is in the enclosure. Try to keep it between 60%-70% until she's finished with the shed. Other than that...just leave her alone. I can only imagine what an itchy and insecure time it is for them.
Re: getting ready to shed...
Yea my guy has never taken a feed while he is in blue. Like JLC said bring up your :snake: humidity and you might even provide a humid hide. The day after the shed offer a feeder. Shed is a stressfull and uncomfortable time for your snake.
Think of it like having to craw on a sunburned belly.